Bearing Assembly

ABSTRACT

A bearing assembly includes at least one outer ring and an inner ring unit having at least two inner rings, each having a central bore. A supporting element extends through the central bores. Roller bodies are rotatably disposed between the at least one outer ring and each of the inner rings. Radially-outer bores extend through the inner ring unit or the supporting element in the axial direction and each receives a screw or bolt for affixing the bearing assembly on a bearing carrier. The radially-outer bores are spaced from the symmetry axis of the bearing assembly. At least one lubrication conduit is defined on or in at least one of the inner rings and is configured to communicate liquid lubricant to the roller bodies.

CROSS-REFERENCE

This application claims priority to German patent application no. 102009 032 294.9, filed on Jul. 9, 2009, which is incorporated fullyherein by reference.

TECHNICAL FIELD

The present invention relates to a bearing assembly comprising at leastone outer ring and an inter ring unit having at least two inner rings,wherein roller bodies are rotatably disposed between the at least oneouter ring and the inner rings.

BACKGROUND

Such a bearing assembly is utilized, e.g., as a two-row tapered rollerbearing, in order to rotatably support a toothed gear wheel in anautomobile engine. For example, the outer ring(s) of two tapered rollerbearings are fitted in complementary mating surfaces of the toothed gearwheel. To attach the toothed gear wheel to an engine housing, the innerrings are retained, e.g., in a corresponding attachment unit, so thatthe toothed gear wheel is rotatably borne on the engine housing. Theattachment unit has an axially-extending bore designed to receive ascrew for threadably attaching the bearing assembly to the enginehousing. Overall, known bearing assemblies of this type have beencharacterized by having a relatively complex construction and byrequiring a time-consuming or expensive installation. In particular, itis relatively time-consuming and/or expensive to precisely set therequired axial pre-loading or tensioning of the two inner rings of thetapered roller bearings against each other before the start of actualoperation of the bearing assembly.

SUMMARY

It is an object of the present teachings to disclose improved bearingassemblies.

For example, in one aspect of the present teachings, bearing assemblieshaving a simplified construction are taught.

In another aspect of the present teachings, bearing assemblies having alubricant conduit, e.g., one or more grooves, channels and/or bores,configured to supply lubricating oil, e.g., from an engine oil reservoirto the roller bodies are disclosed.

In another aspect of the present teachings, bearing assemblies havingadvantageous attachment arrangements for attaching the bearingassemblies to a bearing support or carrier, e.g., an engine housing, aretaught.

In another aspect of the present teachings, a bearing assembly mayinclude at least one outer ring and an inner ring unit having at leasttwo inner rings. A plurality of roller bodies are rotatably disposedbetween the at least one outer ring and the respective inner rings. Aplurality of bores preferably extend through the inner ring unit, e.g.,through the inner rings or through an axial supporting element for theinner rings, in the axial direction and each bore is shaped so as toaccommodate or receive therein at least one attachment element, such ase.g., a bolt or screw. The attachment element preferably serves to affixthe bearing assembly to or on a bearing carrier, such as e.g., an enginehousing. The bores are preferably spaced from an axis of symmetry of thebearing assembly, more preferably they spaced from the axial symmetryaxis. Each inner ring preferably also has an axially-extending centralbore, in which a supporting element is disposed. The inner rings areaxially supportable in a defined manner by the supporting element.

Relative to known bearing assemblies, such a bearing assembly has anoticeably simpler-to-handle structure. For example, the number ofnecessary components forming the bearing assembly may be reduced byproviding the attachment bores within the inner ring unit or the axialsupporting element of the bearing assembly.

In addition or in the alternative, the inner ring unit can havedifferent constructions that are easily adaptable in accordance withparticular design requirements. Optionally, the inner ring unit may bepre-assembled as a whole prior to mounting on the bearing carrier.

If the attachment bores are spaced from the axis of symmetry of thebearing assembly, the supporting element can extend through a centralbore, which is aligned or collinear with the axis of symmetry, in orderto axially support the inner rings against or relative to each other.Such a design may advantageously prevent or minimize the so-called “rundown effect”, which sometimes occurs in tapered roller bearings thatmust, prior to the start of operation, revolve a few times under areduced axial pre-loading of the inner rings relative to each other inorder to set the final, operational position of the tapered rollers.That is, the tapered rollers axially migrate towards an axially-outerrim during the initial revolutions, which is the preferred location ofthe tapered rollers during operation of the bearing assembly. Generallyspeaking, only in this position of the tapered rollers is a problem-freeoperation of the corresponding bearing assembly ensured. Therefore,during the pre-installation procedure for the two-row tapered rollerbearing, it is often necessary to cause the bearing assembly to revolve,e.g., about 15 times at a reduced pre-loading of the inner rings. Assoon as the respective tapered rollers have axially migrated and abut onthe respective outer rims in their final position, the pre-loading ortensioning of the inner rings must then be increased and maintained, sothat the position of the inner rings is fixed and the tapered rollers donot axially migrate together again when the bearing assembly enters intooperation again after the final adjustment.

By disposing the supporting element, which may be a pin or a centeringelement, within the axially central bore, this pre-installation processcan be performed more easily and reliably.

In addition or in the alternative to the above embodiments, at least onelubrication conduit may defined on or in at least one of the inner ringsand is preferably configured to communicate liquid lubricant, e.g. oil,to the roller bodies. The at least one lubrication conduit is preferablya groove, a recess, a channel and/or a bore defined in or one at leastone of the inner rings.

In another aspect of the present teachings, one or both of the innerrings may have a radially-extending chamfer at or on a radially-inwardedge of the outer or side surface that faces the axially-adjacent innerring. Preferably, the outer or side surface of at least one of the innerrings also has a groove that faces the axially-adjacent inner ring,which groove(s) extend(s) in the radial direction outwards from thechamfer(s) and is (are) formed such that lubricant located on thechamfer(s) is transportable radially-outward through the groove(s)defined between the inner rings. By appropriately designing the bearingassembly, it is possible, e.g., to bring or supply lubricant, e.g., oil,from the engine compartment to the chamfer(s), e.g., via theabove-described central bore. The oil is then transportedradially-outward via the chamfer(s) and the groove(s) connected theretoto the outer surface of at least one of the inner rings. The oil thenmoves between the two inner rings into a space, where the roller bodiesare rotatably disposed. The oil can be distributed there and thus canlubricate the roller bodies during operation.

In another aspect of the present teachings, the groove is spiral-shaped,which can be produced in a simple manner when lathing the inner ringsduring the manufacturing process. For example, a lathe tool can bestarted at the chamfer and then drawn radially-outward while the innerring makes, e.g., one revolution. In this case, a spiral-shaped grooveresults, through which the lubricant is transportable between the innerrings from the chamfer. In the alternative, the groove can have anyother arbitrary shape. For example, the groove can extendradially-outward in a linear or otherwise curved manner from the insidesurface of the inner rings.

In another aspect of the present teachings, the supporting element mayhave an at least partially hollow interior and at least one boreextending radially outward from the hollow interior. The bore(s) is(are) preferably designed such that lubricant is transportabletherethrough from the hollow interior of the supporting element, e.g.,to the chamfer(s) and/or groove(s) of the inner ring(s). If the bearingassembly is mounted, e.g., on an engine or an engine compartment of amotor vehicle, the hollow interior can be connected or in communicationwith the oil circulation system of the engine, so that lubricant fromthe engine is transportable through the radially-extending bore(s) tothe groove(s) between the inner rings and ultimately to the rollerbodies.

In addition or in the alternative, the supporting element may beconfigured to perform a centering function, e.g., the supporting elementmay serve to center the inner rings relative to the axial directionthereof.

In another aspect of the present teachings, at least one of the innerrings may have at least one additional groove or channel on or in itsouter side surface that is opposite of the axially-adjacent inner ring.This additional groove is also preferably designed to transportlubricant through it to the central bore or to at least one of theattachment bores. Preferably, the inner ring(s) of this embodiment has(each have) a substantially axially-extending groove or channel on or ina radially-inner surface of the central bore. The substantiallyaxially-extending groove or channel is preferably formed such thatlubricant is transportable through it between the grooves and/orchannels on or in the respective lateral outer side surfaces. If such abearing assembly is mounted on an engine or an engine housing, oil canbe transported from the engine to the outer-lying groove, then to thecentral bore, then to the chamfer(s) and then between the inner rings tothe roller bodies, thereby ensuring an adequate or satisfactorylubrication of the roller bodies.

In another aspect of the present teachings, the bearing assembly mayinclude at least one outer ring and an inner ring unit having at leasttwo inner rings. Roller bodies are again rotatably disposed between theat least one outer ring and the inner rings. A plurality ofaxially-extending bores may be defined in the inner ring unit and eachmay be designed to accommodate or receive at least one attachmentelement, which is configured to affix the bearing assembly to a bearingcarrier. The axially-extending bores are preferably spaced from an axisof symmetry of the bearing assembly, preferably from the axial symmetryaxis. In such an embodiment, substantially the same advantages resultthat were already explained in the above-described bearing assemblies.

The inner ring unit again preferably includes a supporting element thatis disposed within the inner rings, e.g., within a central bore thereofthat is aligned with the axial symmetry axis. The inner rings can beaxially supported in a defined manner by the supporting element.Further, the attachment bore(s) may optionally be defined in thesupporting element, instead of in the inner rings.

In addition or in the alternative, a spacer may be disposed between theinner rings, thereby separating the inner rings in the axial direction.A clamping device, e.g., a tensioning disk, may also be provided. Thespacer, the inner rings and the tensioning disk may be disposed suchthat an axial pre-loading of the inner rings, which is definable orsettable by the tensioning disk, is achieved by the attachment elementfor the bearing assembly mounted on the bearing carrier.

Further advantages, features, objects and embodiments of the inventionwill be readily derivable from the exemplary embodiments described inthe following in conjunction with the appended Figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of a first exemplary embodiment.

FIG. 2 shows an outer view of the exemplary embodiment of FIG. 1.

FIG. 3 shows a cross-sectional view of the exemplary embodiment of FIGS.1 and 2.

FIGS. 4 and 5 show two different cross-sectional illustrations of asecond exemplary embodiment.

FIG. 6 shows a cross-sectional illustration of a third exemplaryembodiment.

FIG. 7 shows a cross-sectional illustration of a fourth exemplaryembodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Each of the additional features and teachings disclosed below may beutilized separately or in conjunction with other features and teachingsto provide improved bearings and/or bearing assemblies, as well asmethods for designing, constructing and using the same. Representativeexamples of the present invention, which examples utilize many of theseadditional features and teachings both separately and in combination,will now be described in further detail with reference to the attacheddrawings. This detailed description is merely intended to teach a personof skill in the art further details for practicing preferred aspects ofthe present teachings and is not intended to limit the scope of theinvention. Therefore, combinations of features and steps disclosed inthe following detail description may not be necessary to practice theinvention in the broadest sense, and are instead taught merely toparticularly describe representative examples of the present teachings.

Moreover, the various features of the representative examples and thedependent claims may be combined in ways that are not specifically andexplicitly enumerated in order to provide additional useful embodimentsof the present teachings. In addition, it is expressly noted that allfeatures disclosed in the description and/or the claims are intended tobe disclosed separately and independently from each other for thepurpose of original disclosure, as well as for the purpose ofrestricting the claimed subject matter independent of the compositionsof the features in the embodiments and/or the claims. It is alsoexpressly noted that all value ranges or indications of groups ofentities disclose every possible intermediate value or intermediateentity for the purpose of original disclosure, as well as for thepurpose of restricting the claimed subject matter.

In FIG. 1, a perspective view of a first representative tapered rollerbearing assembly 1 is shown, which includes an outer ring 3 and aplurality of inner rings, of which only one inner ring 5 is shown due tothe perspective illustration. A radially-encircling orcircumferentially-extending groove 7 is defined in radially-outersurface of the outer ring 3. The outer ring 3 can be connected via thisgroove 7, e.g., with a complementary, not-illustrated toothed gearwheel, with a housing or another element that is desired to rotateduring operation. This connection can take place, e.g., by inserting asecuring ring into the groove 7, which securing ring engages in acorresponding groove within the toothed gear wheel, housing or otherrotatable element.

A central bore (21—see FIG. 2) is formed within the inner rings 5 and apin 9 is inserted into the central bore. The pin 9 serves to axiallysupport the inner ring 5 shown in FIGS. 1 and 2 with a second inner ringnot shown in FIGS. 1 and 2, as will be further explained below with theassistance of FIG. 3. A plurality of axially-extending bores 11 aredefined within the inner ring 5 and are disposed so as to be spacedrelative to the axial symmetry axis of the bearing assembly 1. The bores11 preferably serve to receive carriage bolts, screws or similarattachment devices, by which the bearing assembly can be attached, e.g.,to an engine or engine housing of a motor vehicle or to another type ofbearing carrier/support.

FIG. 2 shows a side view of the tapered roller bearing assembly 1 ofFIG. 1. Again, the outer ring 3, one inner ring 5 and the central bore21 can be recognized. The pin 9 from FIG. 1 is not inserted into thecentral bore 21 shown in FIG. 2 for clarity purposes, although it isunderstood that the pin 9 is normally disposed in central bore 21 duringpre-installation and operation of the bearing assembly 1.

Although six attachment bores 11 are disposed around the central bore 21of FIG. 2, it is understood that fewer (e.g., four, three or only two)or more (e.g., seven, eight, nine, etc.) bores can be provided. Theattachment bores 11 may be disposed symmetrically or equidistantlyrelative to each other or may be arranged in other ways.

A plurality of tapered rollers 23 are rotatably disposed between theouter ring 3 and the inner ring 5 and serve to rotatably bear the outerring 3 relative to the inner rings 5.

The inner ring 5 has a radially-encircling groove or channel 51, e.g.,the groove or channel 51 is preferably circular or torus-shaped. Thisgroove 51 is defined or disposed radially-outward from the attachmentbores 11. A radially-extending groove or channel 53 is defined in or onthe inner ring 5 and extends from the groove 51 to the central bore 21.In a preferred embodiment, the tapered roller bearing assembly 1 ismounted on an engine housing and lubricating oil from the engine issupplied to the groove 51. The lubrication oil can then be transportedalong the groove 51 to the groove 53, regardless of the position of theactual inflow of the oil into the groove 51, and thereby into thecentral bore 21. An axially-extending groove (not illustrated in FIG. 2)defined or disposed on a radially-inner surface of the central bore 21connects to the groove 53. In this case, the lubricating oil can betransported between the inner rings 5 a and 5 b via thisaxially-extending groove. In the alternative, the groove 53 may bedesigned to feed into one (or more) of the bores 11 and in this case,the lubricant is communicated therein via a corresponding groove in ananalogous manner. In another alternative, the groove 53 can be formed inanother geometric shape, e.g., it can be spiral-shaped or otherwisecurved.

FIG. 3 shows a cross-sectional illustration of the tapered rollerbearing assembly of FIGS. 1 and 2 along the axial direction thereof fromthe center or axis of symmetry to the radially-outer edge of the bearingassembly 1.

This tapered roller bearing assembly 1 includes a one-piece outer ring 3having the above-described groove 7 defined in an axially middleposition of the outer ring 3. Two obliquely-extending track surfaces fortapered rollers 31 are formed or defined on the lower surface of theouter ring 3. The bearing assembly 1 includes two inner rings 5 a and 5b, each of which also has a corresponding track surface for the taperedrollers 31. Thus, the embodiment of FIG. 3 is a two-row tapered rollerbearing assembly 1 in the so-called O-arrangement with a one-piece outerring 3 and a two-piece inner ring 5 a and 5 b. Each of the two taperedroller bearings comprises a set of tapered rollers 31 guided inrespective cages 33.

Each of the inner rings 5 a and 5 b has a central bore 21. The pin 9 isdisposed within the central bore 21 and may preferably perform at leasttwo functions. For one, a press-fit between the outer surface of the pin9 and the inner surface of the central bore 21 can be achieved bysuitably dimensioning the pin 9 and the central bore 21 of the innerrings 5 a and 5 b. Due to the press-fit, e.g., ISO tolerance N6, of thepin 9 in the inner rings 5 a and 5 b, an axial pre-loading or tensioningor biasing of the inner rings 5 a and 5 b can be defined in a reliablemanner. Thus, it is possible, in particular, to set or determine theamount of the pre-loading or pre-tensioning of the inner rings 5 a, 5 bin a well-defined manner already during the production orpre-installation of the bearing assembly 1. The pin 9 includes an endportion 37 having a reduced diameter outside of the intrinsic bearingassembly. A supplemental stabilizing and/or securing of the bearingassembly 1 can be achieved by inserting the end portion 37 of the pin 9,e.g., into an abutting locking washer or a supporting disk, therebyretaining it.

The inner rings 5 a and 5 b each have at least one attachment bore 11 aand 11 b, respectively. The bores 11 a and 11 b extend in the axialdirection through the respective inner rings 5 a, 5 b. The inner rings 5a and 5 b are arranged so that the bores 11 a and 11 b extend in acollinear manner. Each of the bores 11 a and 11 b has two portions 39 aand 41 a, 39 b and 41 b, respectively, of different diameters. In thiscase, for example, a not-illustrated carriage bolt can be inserted fromthe right into the bore 11 a as shown in the illustration of FIG. 3. Thecarriage bolt goes through the portions 41 a, 39 a, 39 b and 41 b and,if it has sufficient length, its threaded end emerges again from thebore 11 b. As a result, the entire tapered roller bearing assembly 1 canbe attached, e.g., to an engine housing of a motor vehicle via thethreads of the carriage bolt that axially project beyond the bore 11 b.The head of the carriage bolt can be countersunk within the portion 41 aof the inner ring 5 having the larger diameter, so that a compactmounted structure is achieved, thereby minimizing installation spacerequirements.

In such an embodiment, the portion 41 b of the inner ring 5 b having thelarger diameter is not necessary for any particular functional purpose.However, the inner rings 5 a and 5 b are preferably constructedidentically for manufacturing reasons, so that the required number ofdifferent components for the tapered roller bearing assembly 1 can bereduced. The assembly 1 as a whole is preferably mirror-symmetric fromthe outer ring 3 to the pin 9 relative to a plane extending in theradial direction between the inner rings 5 a and 5 b.

In this embodiment, each of the inner rings 5 a and 5 b has a chamfer 61defined on a lower edge end adjacent to the central bore 21. The chamfer61 preferably extends in a circumferential manner entirely around eachof the inner rings 5 a, 5 b. Another not-illustrated groove or channelpreferably extends in the radial direction from the chamfers 61 alongeach of the respective facing side surfaces 63 of the inner rings 5 aand 5 b and into the hollow chamber between the tapered roller bodies31. In the alternative, such a groove or channel can also be formed onlyin or on one side surface 63 of the inner rings 5 a or 5 b. Such agroove ensures that lubricating oil, e.g., motor oil from the engine,reaches the roller bodies 31 during the operation and corresponds to agroove-like recess 127 of the next embodiment, as will be furtherdiscussed below.

As was already explained in connection with FIG. 2, the lubricating oilis received by the groove 51, is then transported via the groove 53 tothe central bore 21 up to the chamfer 61 and then between the outersurfaces 63 of the inner rings 5 a and 5 b and finally to the taperedroller bearings 31. Another groove can be provided on or in theradially-inner surface of the central bore to assist in transporting theoil between the inner rings 5 a, 5 b, as was discussed above.

FIG. 4 shows a second representative tapered roller bearing assembly 101that includes two tapered roller bearings, each having an outer ring103, an inner ring 105, a plurality of roller bodies 107 and a cage 109for retaining the roller bodies 107. The outer rings 103 are fitted intocorresponding mating surfaces of a toothed gear wheel 111. The innerrings 105 each have a central bore and a centering element 113 isinserted in the central bore. Due to the centering element 113, theinner rings 105 can be pre-installed in a pre-loaded manner with apress-fit in a manner analogous to the pin 9 of the exemplary embodimentof FIGS. 1 to 3.

The inner rings 105 also have attachment bores 115 lying outside of theaxial symmetry axis, which bores 115 are disposed in a manner analogousto the bores 11 of the embodiment of FIGS. 1 to 3. Attachment screws orbolts 117 may be inserted into the bores 115.

Further, the centering element 113 has a first hollow space 118 that isseparated from a second hollow space 121 by a separating wall 119. Theseparating wall 119 has a radially-encircling orcircumferentially-extending recess or channel 123 and at least one bore125 extending radially outward from the recess 123. The function of thebore 125 will be explained with the assistance of FIG. 5.

In FIG. 5, the tapered roller bearing assembly 101 of FIG. 4 is shown ina cross-sectional illustration from another angular position, i.e. theassembly 101 has been rotated about its central axis relative to theillustration of FIG. 4 so that the cross-section does not extend throughthe bore 115 and the attachment screw 117, but rather extends throughthe part of the inner rings 105 that lies between two screws 117. Thus,in FIG. 5, the bore 125 lies in the plane of the cross-sectionalillustration.

It is also illustrated here that the inner rings 105 each have agroove-like recess or channel 127 defined on the outer side surfacesthat face each other in the axial direction. At least one of therecesses 127 is designed such that the bore 125 is connected or incommunication with the recess 127. Consequently, the hollow spacebetween the tapered rollers 107 is connected or in communication withthe hollow space 118 of the centering element 113 via the recesses 127and the bore 125. Lubricating oil from the engine compartment can flowinto the hollow space 118 and then can be transported via the bore 125and the recess(es) 127 to the tapered rollers 107, thereby ensuring anadequate or satisfactory lubrication of the tapered roller bearingassembly 101 during operation.

In the alternative, instead of the recess(es) or channel(s) 127 definedon the inner rings 105, it is possible to provide a chamfer and aspiral-shaped-extending groove in a manner analogous to the exemplaryembodiment of FIG. 3. If the chamfer is provided, it is not necessaryfor the bore 125 to lie directly at the starting point of thespiral-shaped groove. If the chamfer radially encircles orcircumferentially extends around the entire inner ring 105, the bore 125is always connected or in communication with the spiral-shaped-extendinggroove, thereby ensuring an unhindered flow of lubricating oil from thehollow space 118 to the tapered rollers 107. The sole prerequisitetherefor is that the bore 125 lies precisely between the inner rings 105with reference to the axial direction.

In contrast to the embodiment of FIG. 3, the attachment bore 115 and thescrew head of the screw 117 of this embodiment are preferablydimensioned to prevent an axial migration of the centering element 113in the direction of the screw head. This is ensured by designing thescrew head so that it radially overlaps the centering element 113,thereby bounding or limiting the axial movement of the centering element113. That is, the screw head acts as an axial stop for the centeringelement 113.

A further embodiment of the invention is illustrated in FIG. 6, which issubstantially the same as the exemplary embodiment of FIGS. 4 and 5 withthe difference that separate or discrete outer rings are not present.Instead, the track surfaces for the tapered rollers 207 are directlymachined into the lower surface of the toothed gear wheel 211. Thenumber of the necessary components is thus further reduced as comparedto the embodiment of FIGS. 4 and 5.

In FIG. 6, it can also be recognized, in an exemplary manner, how thebearing assembly 201 may be attached to the engine housing 231 by ascrew 217. The screw 217 goes through the two inner rings 205 in theaxially-extending bores provided therefor and engages in a correspondingthread in the engine housing 231.

In the illustration of FIG. 6, the function of the centering unit 213 isalso further demonstrated. The centering unit 213 projects in the axialdirection beyond the inner ring 205 that directly borders the enginehousing 231. Thus, the centering unit 213 mates or engages in acorresponding or complementary recess in the engine housing 231 and thusensures a perfectly-fitted centering of the bearing assembly 201 on theengine housing 231. An axial migration or shifting of the centeringelement 213 during operation is thus effectively prevented on the oneside by the engine housing 231 and on the other side by the screw headof the screw 217.

In the embodiment of FIGS. 1 to 3, a suitably axially-elongated pin 9can perform the function of preventing axial migration or shifting.

In FIG. 7, a fourth representative tapered roller bearing assembly 301includes outer rings 303 in a manner analogous to the exemplaryembodiments of FIGS. 4 and 5. The outer rings 303 are fitted intocomplementary mating surfaces of a toothed gear wheel 305. The taperedroller bearing assembly 301 further includes two inner rings 307 thatare rotatably disposed on the outer rings 303 via two sets of taperedrollers 309. The tapered rollers 309 are each guided in respective cages311. A centering element 313 serves to center the tapered roller bearingassembly 301 in a not-illustrated housing in a manner analogous to theexemplary embodiments of FIGS. 4 to 6. It also has a radially-extendingbore 315, via which lubricant can be guided to the space between thetapered rollers 309.

In contrast to the exemplary embodiments of FIGS. 4 to 6, the attachmentbores 317 are defined in the centering element 313 so as to be spaced inthe radial direction from the axial symmetry axis. The attachment bores317 are again adapted or designed to receive, e.g., attachment screws orcarriage bolts. Thus, the tapered roller bearing assembly 301 can beattached to a housing or a bearing carrier by the screws or boltsextending through the centering element 313, rather than throughattachment bores defined in the inner rings 307 as in the previousembodiments.

The inner rings 307 are disposed on a seating surface 321 so as to bespaced in the axial direction by a spacer element 319 disposed betweenthem. Further, a tensioning ring 323 is provided that is also disposedon the seating surface 321. The centering element 321 includes aflange-like extension 325 that extends radially outward such that itengages behind one of the inner rings 307. When the screws are nowinserted into the bores 317 and thus the tensioning disk is supported ona corresponding housing, a well-defined axial pre-loading orpre-tensioning of the two inner rings 307 can be achieved by thecooperation of the tensioning disk and a defined clamping torque of thescrew. The axial pre-loading or axial clamping of the inner rings 307 isnecessary for the operation of the tapered roller bearing assembly 301in a manner similar to the previous embodiments.

Although many of the lubrication conduits have been depicted as grooves(e.g., 51, 53, 127, etc.) that are open to the surface, such lubricationconduits can be embodied as channels or bores that are completelydefined within the inner rings, such that the lubricant is transportedthrough the inner ring(s) rather than on an outer surface of the innerring(s).

REFERENCE NUMBER LIST

-   1 Tapered roller bearing assembly-   3 Outer ring-   5, 5 a, 5 b Inner ring-   7 Radially-encircling groove-   9 Pin-   11, 11 a, 11 b Bore-   21 Central bore-   23 Tapered roller-   31 Tapered roller-   33 Cage-   37 Portion of pin 9 having a reduced diameter-   39 a, 39 b Portion of bores 11 a and 11 b, respectively, having a    smaller diameter-   41 a, 41 b Portion of bores 11 a and 11 b, respectively, having a    larger diameter-   51 Groove-   53 Groove-   61 Chamfer-   63 Outer side surface of inner rings 5 a, 5 b-   101 Tapered roller bearing assembly-   103 Outer ring-   105 Inner ring-   107 Tapered roller-   109 Cage-   111 Toothed gear wheel-   113 Centering element-   115 Bore-   117 Attachment screw-   118 Hollow interior-   119 Separating wall-   121 Hollow interior-   123 Recess-   125 Bore-   127 Recess-   201 Tapered roller bearing assembly-   205 Inner ring-   207 Tapered roller-   211 Toothed gear wheel-   213 Centering element-   217 Screw-   231 Engine housing-   301 Tapered roller bearing assembly-   303 Outer ring-   305 Toothed gear wheel-   307 Inner ring-   309 Tapered roller-   311 Cage-   313 Centering element-   315 Bore-   317 Screw-   319 Spacer element-   321 Seating surface-   323 Tensioning ring-   325 Extension

1. A bearing assembly comprising: at least one outer ring, an inner ringunit having at least two inner rings, each inner ring having a centralbore extending in an axial direction, a supporting element extendingthrough the central bores and supporting the inner rings in the axialdirection, and a plurality of roller bodies rotatably disposed betweenthe at least one outer ring and each of the inner rings, wherein aplurality of radially-outer bores also extend in the axial directionthrough one of the inner ring unit and the supporting element and eachis configured to receive at least one attachment device, by which thebearing assembly is affixable on or to a bearing carrier, wherein theradially-outer bores are spaced from an axis of axial symmetry of thebearing assembly.
 2. A bearing assembly according to claim 1, wherein achamfer is defined on a radially-inward edge of at least one of theinner rings, the chamfer extending continuously in a circumferentialdirection of the inner ring and facing the axially-adjacent inner ring.3. A bearing assembly according to claim 2, wherein at least one grooveis defined on an outer surface of at least one of the inner rings on aside facing the axially-adjacent inner ring, the groove extends radiallyoutward from the chamfer and is formed such that lubricant istransportable radially outwardly from the chamfer via the at least onegroove between the inner rings.
 4. A bearing assembly according to claim3, wherein the groove is spiral-shaped.
 5. A bearing assembly accordingto claim 3, wherein the supporting element has an at least partiallyhollow interior and a radially-extending bore is defined in thesupporting element such that lubricant is transportable through theradially-extending bore from the hollow interior to the at least onechamfer.
 6. A bearing assembly according to claim 3, wherein a circulargroove is defined on or in at least one of the inner rings on an outerside surface that faces away from the other axially-adjacent inner ringand a radially-extending groove extends from the circular groove to aninner edge of the at least one inner ring, wherein lubricant istransportable via the circular groove and the radially-extending grooveto the central bore or to at least one of the bores for the attachmentelements.
 7. A bearing assembly according to claim 6, wherein anaxially-extending groove is defined on or in a radially-inner surface ofthe central bore of at least one of the inner rings, theaxially-extending groove being formed such that lubricant istransportable through it between the radially-extending grooves onopposite outer side surfaces of the at least one inner ring.
 8. Abearing assembly according to claim 1, wherein the supporting element ispress-fit in the central bores of the inner rings.
 9. A bearing assemblyaccording to claim 1, wherein a securing groove is defined on an outercircumference of the at least one outer ring.
 10. A bearing assemblyaccording to claim 1, wherein the outer ring is a part of a toothed gearwheel and has teeth extending radially outward.
 11. A bearing assemblycomprising: at least one outer ring, first and second inner ringsdisposed axially adjacent to each other, each inner ring having a firstbore extending in an axial direction along an axis of symmetry of theinner rings, a support extending through the first bores of the innerrings and supporting the inner rings in the axial direction, and aplurality of roller bodies rotatably disposed between the at least oneouter ring and each of the inner rings, wherein at least one lubricationconduit is defined in or on one or both axially-adjacent side surfacesof the first and second rings, the at least one lubrication conduitextending at least partially in a radial direction of the inner ringsand being in fluid communication with a chamber containing the rollerbodies, and wherein a plurality of second bores extend in the axialdirection in parallel with the first bore through one of the inner ringsand the support, each second bore being configured to receive at leastone attachment device, by which the bearing assembly is affixable on orto a bearing carrier.
 12. A bearing assembly according to claim 11,wherein at least a portion of the at least one lubrication conduit isselected from the group consisting of a groove, a recess, a channel anda bore defined in or on at least one of the inner rings.
 13. A bearingassembly according to claim 12, wherein the at least one attachmentdevice is selected from a carriage bolt and a screw.
 14. A bearingassembly according to claim 13, wherein each second bore has a firstportion and a second portion having a diameter larger than the firstportion, the second portion being configured to receive a head of theattachment device in a countersunken manner.
 15. A bearing assemblyaccording to claim 13, wherein each second bore has a substantiallyconstant diameter.
 16. A bearing assembly according to claim 13, whereinthe support has an at least partially hollow interior configured toreceive lubricant and at least one bore in fluid communication with boththe hollow interior of the support and the at least one lubricationconduit.
 17. An apparatus comprising: a bearing carrier and a bearingassembly according to claim 13, wherein attachment devices are disposedin each of the second bores and terminal axial ends of the attachmentdevices threadably engage the bearing carrier and wherein the attachmentdevices each have a head that is larger than a body portion disposedwithin the second bores, the heads at least partially overlapping thesupport in the radial direction on an axial end opposite of thethreadable engagement of the attachment devices with the bearingcarrier.
 18. An apparatus according to claim 17, wherein the bearingcarrier is one of an engine and an engine housing of a motor vehicle.19. An apparatus according to claim 18, further comprising gear teethdisposed on a radially-outer portion of the bearing assembly.
 20. Anapparatus according to claim 18, wherein the support has an at leastpartially hollow interior configured to receive lubricant and at leastone bore in fluid communication with both the hollow interior of thesupport and the at least one lubrication conduit.